The Unix shell has been around longer than most of its users have been alive.
It has survived so long because it’s a power tool
that allows people to do complex things with just a few keystrokes.
More importantly,
it helps them combine existing programs in new ways
and automate repetitive tasks
so they aren’t typing the same things over and over again.
Use of the shell is fundamental to using a wide range of other powerful tools
and computing resources (including “high-performance computing” supercomputers).
These lessons will start you on a path towards using these resources effectively.

Prerequisites

This lesson guides you through the basics of file systems and the
shell. If you have stored files on a computer at all and recognize
the word “file” and either “directory” or “folder” (two common words
for the same thing), you’re ready for this lesson.

If you’re already comfortable manipulating files and directories,
searching for files with grep and find, and writing simple loops
and scripts, you probably want to explore the next lesson: shell-extras.